The invention concerns an analyzer, typically for analyzing body fluids, that has one or more exchangeable cassettes (consumables) which contain operating liquids, operating agents and/or consumables, and which can be inserted into appropriate holders of the analyzer wherein the analyzer comprises a system for the exchange of ambient air which has a filter unit on the inlet side of the analyzer. In addition the invention concerns cassettes which can be inserted into such an analyzer in an exchangeable manner and which contain operating fluids, operating materials and/or consumables for the operation of the analyzer.
Exchangeable consumables refers to exchangeable consumables or containers or packs which contain consumables which can be exchanged regularly (for example, when a certain period has elapsed, or when a certain number of measurements has been carried out, or when a certain amount of operating material has been consumed) and can be inserted by operating personnel into an analyzer and, in particular, into an analyzer for analyzing body fluids.
Such analyzers for analyzing body fluids are, for example, developed as portable analyzers for determining POC (point of care) parameters, i.e., the blood gases (O2, CO2, pH), the electrolytes (e.g., K+, Na+, Ca++, Cl−), the metabolites (e.g., glucose and lactate), the haematocrit, the haemoglobin parameters (e.g., tHb, SO2, etc.) and bilirubin, and are primarily used for the decentralized determination of the above-mentioned parameters in whole blood samples. Applications in veterinary medicine and the use of serum, plasma, urine and dialysate samples are possible.
Ideally it should also be possible for “untrained” users to simply and intuitively operate such analyzers. Another advantageous feature is when the instrument can be operated “virtually maintenance free” from the point of view of a user. “Virtually maintenance free” is generally understood as a system that requires as little maintenance as possible in which even a (technically) untrained user can only exchange consumables that are present in the form of cassettes and/or modules for the routine operation similar to for example an inkjet printer. It should be possible for the user to exchange all consumables by simple intuitive handling steps.
In one possible concept of such an analyzer, materials that are consumed can for example be combined as follows into consumables:
Consumable 1: Sensor cassette which contains all or at least some of the sensors required for the analyte determination.
Consumable 2: Liquid container or fluid pack which contains the functional fluids required to operate the analyzer (e.g., calibration solutions, washing solutions, reference liquids, certain reagent solutions required for the operation, etc.). It can optionally also contain further elements or functionalities such as the entire fluidic system or parts thereof, the sample input device or also further sensory components.
Consumable 3: Printer paper for an internal printer.
Consumable 4: Optionally further consumables may be provided, for example a cassette with reference solutions in ampoules for carrying out an automated quality control (aQC), which the user himself should be able to exchange by simple intuitive handling steps.
The subdivision of the consumables described above is only intended as an example of an embodiment variant. It is also conceivable that (partial) functionalities or (partial) elements of several consumables are combined so that for example fewer consumables or even only one consumable is required. On the other hand, it is also conceivable that (partial) functionalities or (partial) elements of individual consumables are distributed among several consumables.
The consumables are connected to one another and to the analyzer by matching interfaces e.g., in the form of fluidic docking nipples. The consumables can be mechanically connected to their respective counterparts by a simple manual sequence of movements either directly by the user or by drives located in the device which automatically carry out the coupling after the user has only brought the cassette into “position.” or into a corresponding holder.
Medical analyzers have many electronic components which require an ambient temperature which is as constant as possible for a reliable operation.
Furthermore, the temperature of the sensory areas of the analyzer often also have to be kept constant within certain temperature ranges in order to provide the sensors with an operating environment that is as ideal as possible. Thus, for example enzyme sensors for glucose or lactate determination have to be maintained at a temperature of 30° C. for reasons of storage stability whereas for example sensors for blood gas determination can also be preferably operated at 37° C.
The functional fluids that are for example contained in the fluid pack also have certain preferred temperature conditions. Thus, for example certain solutions can be made stable for longer periods by storing them at lower temperatures.
Furthermore, medical analyzers are used worldwide under very different climatic boundary conditions which is why they have to reliably operate in a large range of temperatures and/or air humidities.
In summary it is apparent that medical analyzers have to have a reliable good temperature management and must have devices for this purpose which enable a controlled operating temperature that is as independent as possible of environmental conditions and the current operating status of the analyzer.
One component of the temperature management of such medical analyzers are ventilation systems which can dissipate waste heat in a directed manner by for example sucking in the surrounding air via special ventilation channels for cooling.
Since foreign bodies contained in the surrounding air (e.g., dust, particles, moisture droplets) are also sucked in and can thus reach the interior of the analyzer, such ventilation systems have air filters especially in their suction ducts which filter the sucked air in order to protect as far as possible the interior of the analyzer from such contaminations.
Separators are generally referred to as air filters which filter out undesired suspended matter such as microorganisms, pollen, dust or gases from the air. These are filtering separators which remove substances from an air flow in a filter medium. Usually fibres or particles are used as a filter medium (collectors). A distinction is for example made between fiber layer filters, granular bed filters and filters with a solid medium (more rarely such as sinter layers, ceramics).
As a result of the flow of surrounding air through the air filter, impurities accumulate on the inner surfaces of the air filter which reduces its filtering efficiency during the course of use.
In order to ensure that there is as far as possible always a good filtering efficiency and in particular a high rate of air flow while retaining all possible suspended matter, air filters have to therefore be exchanged at regular intervals.
Such exchange steps have previously had to be carried out in known instruments by the operator who manually had to remove the contaminated air filter from the instrument and had to replace it by a new air filter.
Since such exchange processes are not part of the daily routine operation of a medical analyzer they are not given priority in training and practice, so that they are therefore more subject to errors or generally omitted.
In addition the periods of use of such air filters in an instrument and also their degree of contamination is often not monitored so that the user would have no indication that an air filter replacement is due.
Air filters are configured as additional consumables in the analyzers known in the prior art which are inserted into the analyzer and which require a separate training in their handling and separate stock keeping. This can result in problems in handling (e.g., incorrect insertion) or also problems in their availability (lack of stock).
The result of such problems can for example be a defective analyzer due to contaminations that have entered or the analyzer may be temporarily blocked for further measurements due to incorrect temperature control.